Investigation of large α production in reactions involving weakly bound Li7

Abstract

The origin of the large $\ensuremath{\alpha}$-particle production cross sections in systems involving weakly bound $^{7}\mathrm{Li}$ projectiles has been investigated by measuring the cross sections of all possible fragment-capture as well as complete fusion using the particle-$\ensuremath{\gamma}$ coincidence, in-beam, and off-beam $\ensuremath{\gamma}$-ray counting techniques for the $^{7}\mathrm{Li}+^{93}\mathrm{Nb}$ system at near Coulomb barrier energies. Almost all of the inclusive $\ensuremath{\alpha}$-particle yield has been accounted for. While the $t$-capture mechanism is found to be dominant ($\ensuremath{\sim}70%$), compound nuclear evaporation and breakup processes contribute $\ensuremath{\sim}15%$ each to the inclusive $\ensuremath{\alpha}$-particle production in the measured energy range. Systematic behavior of the $t$ capture and inclusive $\ensuremath{\alpha}$ cross sections for reactions involving $^{7}\mathrm{Li}$ over a wide mass range is also reported.